News sites around the world have shown Khalid al-Hamad sink his teeth into what appears to be the lung of a dead Syrian government soldier. His fellow rebels have called for him to be arrested or killed for the act. Human-rights groups have condemned him. But al-Hamad has no regrets.

In an interview conducted via Skype in the early hours of May 14, al-Hamad explained to TIME what caused him to cut out the soldier’s organs: “We opened his cell phone, and I found a clip of a woman and her two daughters fully naked and he was humiliating them, and sticking a stick here and there.”

The video, a 27-second clip in which al-Hamad brandishes organs that appear to be the lungs and heart of the Syrian soldier who lies dead at al-Hamad’s feet, was first seen by two TIME reporters in April. A few weeks later, TIME obtained a copy. Though we had been told by witnesses to the filming that the video was legitimate, we set about authenticating its content, aware of the potential that it could have been faked for propaganda purposes. Al-Hamad has now confirmed that the video is real, and that he did indeed take a bite of the soldier’s lung. (At the time of filming, al-Hamad believed he was biting into the liver. A surgeon who has seen the video confirms that the organ in question was a lung, which somewhat resembles the liver). On May 12, a copy of the video appeared on a proregime website, sparking a flood of Facebook Shares and YouTube views.

Al-Hamad, who is Sunni and harbors a sectarian hatred for Alawite Muslims, said he has another gruesome video of his killing a government soldier from the Alawite faith. (Syrian President Bashar Assad is Alawite; the conflict in Syria is increasingly sectarian.) “Hopefully we will slaughter all of them [Alawites]. I have another video clip that I will send to them. In the clip, I am sawing another shabiha [progovernment militiaman] with a saw. The saw we use to cut trees. I sawed him into small pieces and large ones.” Al-Hamad also explained that even though both sides of the conflict in Syria are using video clips of their own brutal actions to intimidate the other, he believes his clip would have particular impact on the regime’s troops. “They film as well, but after what I did hopefully they will never step into the area where Abu Sakkar is,” he said, using his nom de guerre and referring to the part of Syria he currently controls.

Human Rights Watch (HRW), which validated the video, released a report on May 13 identifying al-Hamad as a well-known commander responsible for the recent cross-border shelling of a Shi‘ite Lebanese village that killed two. The organization called on the U.N. Security Council to refer the Syria situation to the International Criminal Court to ensure accountability for all war crimes and crimes against humanity. “It is not enough for Syria’s opposition to condemn such behavior or blame it on violence by the government,” said Nadim Houry, HRW’s deputy director for the Middle East. “The opposition forces need to act firmly to stop such abuses.” Al-Hamad lashed out at HRW and the U.N. for focusing on opposition abuses when the regime is responsible for similar atrocities. During the interview, he sent links to YouTube videos purporting to show regime abuses. “Why doesn’t the U.N. make an appeal for the shabiha not to do that? The shabiha themselves posted a million clips of them stabbing and raping.”

Al-Hamad, who has been fighting on the front lines near the strategic town of al-Qusayr for the past week, said the video captures the first time he had ever attempted to eat an enemy’s liver. He indicated that the brutality of the regime had driven him to extremes. “You are not seeing what we are seeing, and you are not living what we are living. Where are my brothers, my friends, the girls of my neighborhood who were raped? May God bless them all.”

The Supreme Military Council, which according to the leadership oversees about 90% of the fighting groups in Syria, has issued a poster — circulated on Facebook — calling for al-Hamad’s arrest, saying it wants him “dead or alive.” In response, supporters have posted stylized portraits of al-Hamad cradling a rifle. “We Love You,” reads the inscription.

Al-Hamad pointed out in the interview that the revolution started as a peaceful uprising more than two years ago. “[The Alawites] were the ones who killed our children in Baba Amr and raped our women,” he said, referring to the site of a ferocious battle in the city of Homs that took place in February 2012. Then, referring to the recent massacre of Sunni villagers near the coastal village of Baniyas that has been attributed by rebel groups to the regime, he adds, “They were the ones who slaughtered the children and women in Bayda [near Baniyas]. We didn’t start it, they started it.” He swore to avenge every death. “Our slogan is: An eye for an eye, and a tooth for a tooth.”

Aryn Baker is the Middle East Bureau Chief for TIME, covering politics, society, culture, religion, the arts and the military in the greater Middle East, including Pakistan and Afghanistan. She currently resides in Beirut, Lebanon.